Mauch MIREX 2010

function CPD = update_ess(CPD, fmarginal, evidence, ns, cnodes, hidden_bitv)

% UPDATE_ESS Update the Expected Sufficient Statistics of a hhmm Q node.

% function CPD = update_ess(CPD, fmarginal, evidence, ns, cnodes, idden_bitv)

%

% we assume if one of the Qps is observed, all of them are 

% We assume the F nodes are already hidden 

% Figure out the node numbers associated with each parent

dom = fmarginal.domain;

self = dom(CPD.self_ndx);

old_self = dom(CPD.old_self_ndx);

%Fself = dom(CPD.Fself_ndx);

%Fbelow = dom(CPD.Fbelow_ndx);

Qps = dom(CPD.Qps_ndx);

Qsz = CPD.Qsz;

Qpsz = CPD.Qpsz;

% hor_counts(old_self, Qps, self),

% fmarginal(old_self, Fbelow, Fself, Qps, self)

% hor_counts(i,k,j) = fmarginal(i,2,1,k,j) % below has finished, self has not

% ver_counts(i,k,j) = fmarginal(i,2,2,k,j) % below has finished, and so has self (reset)

% Since any of i,j,k may be observed, we write

% hor_counts(ndx{:}) = fmarginal(...)

% where e.g., ndx = {1, ':', 2} if Qps is hidden but we observe old_self=1, self=2.

% ndx{i,k,j}

if hidden_bitv(old_self)

  ndx{1} = ':';

else

  ndx{1} = evidence{old_self};

end

if hidden_bitv(Qps)

  ndx{2} = ':';

else

  ndx{2} = subv2ind(Qpsz, cat(1, evidence{Qps}));

end

if hidden_bitv(self)

  ndx{3} = ':';

else

  ndx{3} = evidence{self};

end

fmarg = add_ev_to_dmarginal(fmarginal, evidence, ns);

% marg(Qold(t-1), Fbelow(t-1), Fself(t-1), Qps(t), Qself(t))                            

hor_counts = zeros(Qsz, Qpsz, Qsz);

ver_counts = zeros(Qpsz, Qsz);

if ~isempty(CPD.Fbelow_ndx)

  if ~isempty(CPD.Fself_ndx) % general case

    fmarg.T = myreshape(fmarg.T, [Qsz 2 2 Qpsz Qsz]);

    marg_ndx = {ndx{1}, 2, 1, ndx{2}, ndx{3}};

    hor_counts(ndx{:}) = fmarg.T(marg_ndx{:});

    ver_counts(ndx{2:3}) = ... % sum over Fbelow and Qold=i

	sum(fmarg.T({ndx{1}, 1, 2, ndx{2}, ndx{3}}),1) + ..

	sum(fmarg.T({ndx{1}, 2, 2, ndx{2}, ndx{3}}),1);

  else % no F from self, hence no startprob

    fmarg.T = myreshape(fmarg.T, [Qsz 2 Qpsz Qsz]);

    hor_counts(ndx{:}) = fmarg.T({ndx{1}, 2, ndx{2}, ndx{3}});

  end

else % no F signal from below

  if ~isempty(CPD.Fself_ndx) % self F

    fmarg.T = myreshape(fmarg.T, [Qsz 2 Qpsz Qsz]);

    hor_counts(ndx{:}) = fmarg.T({ndx{1}, 1, ndx{2}, ndx{3}});

    ver_counts(ndx{2:3}) = ... % sum over Qold=i

	sum(fmarg.T({ndx{1}, 2, ndx{2}, ndx{3}}),1);

  else % no F from self

    error('An hhmmQ node without any F parents is just a tabular_CPD')

  end

end

CPD.sub_CPD_trans = update_ess_simple(CPD.sub_CPD_trans, hor_counts);

if ~isempty(CPD.sub_CPD_start)

  CPD.sub_CPD_start = update_ess_simple(CPD.sub_CPD_start, ver_counts);

end